Small-molecule inhibitors of various classes of kinases have become significant exploratory medicinal compounds. However, certain kinase inhibitors possess properties of low water solubility and poor oral bioavailability.
Among the various classes of kinases for which experimental small-molecule inhibitors have been developed are the family known as Focal Adhesion Kinase. Focal adhesion kinase (FAK) has recently been established as a key component of the signal transduction pathways triggered by integrins. Aggregation of FAK with integrins and cytoskeletal proteins in focal contacts has been proposed to be responsible for FAK activation. Recent results from a number of different approaches have shown that integrin signaling through FAK leads to increased cell migration on fibronectin as well as potentially regulating cell proliferation and survival. J L Guan (1997 August-September), Int J Biochem Cell Biol., 29(8-9):1085-96. Interaction with integrin and focal adhesion kinase (FAK) regulates the cancer cell adhesion and invasion into extracellular matrix (ECM). In addition, phosphorylation of FAK correlates with the increase of cell motility and invasion. Adhesion and spreading of cancer cells on a variety of ECM proteins, including collagen type IV, leads to an increase in tyrosine phosphorylation and activation of FAK. H Sawai, et al. (2005), Molecular Cancer, 4:37.
Certain compounds of the 2,4-diaminopyridine class of inhibitors show promise in the treatment of malconditions that may be affected by FAK, such as proliferative disorders such as cancer and inflammatory disorders such as arthritis. See, for example, published PCT application WO2008/115369, wherein compounds of this type are disclosed. For effective therapeutic use, such compounds must be formulated to provide adequate pharmacokinetic properties, such as AUC. Oral administration of compounds is generally preferred by the patient population, so oral formulations providing favorable pharmacokinetics are needed.